non-invasive trigeminal and vagus nerve stimulation for stroke subjects with chronic upper extremity deficits

Conditions: Stroke, Ischemic; Upper Extremity Paresis

Summary: this is a single-center, pilot study of up to 25 subjects with residual upper extremity deficits at least six months after an ischemic stroke. the purpose of the study is to evaluate the initial clinical safety, device functionality, and treatment effect of non-invasive electrical stimulation of the trigeminal and/or vagus nerves (ntvns) using the neurastasis stimulator system adjunctive to rehabilitation. subjects will either receive the intervention or control-sham stimulation. the study will inform the design and implementation of a pivotal study.

this pilot study will proceed in two phases: phase i, an unblinded blinded stage and phase ii, a blinded stage comparing intervention and sham groups. phase i will consist of 5 subjects, unblinded, receiving ntvns. this phase will test the usability of the device and de-risk the use of ntvns during rehabilitation. visits will include consent and baseline evaluation followed by 6 weeks of treatment consisting of the standard of care with ntvns. rehabilitation and treatment will occur at a cadence of 3 sessions per week. primary endpoints will be collected after 6 weeks. phase ii will consist of a prospective randomized open, blinded endpoint (probe) design. subjects will be randomized to an intervention ntvns group or a control sham stimulation group. the control sham stimulation consists of standard-of-care rehabilitation with only a minimal amount of ntvns delivered at the start of each session during a tolerability assessment intended to support further blinding for therapists and subjects. the same evaluations, sessions, and endpoints will occur as those in phase i.

Eligibility criteria:
inclusion criteria: * history of unilateral supratentorial ischemic stroke that occurred at least 6 months but not more than 10 years prior to enrollment. * age \>40 years and \<80 years. * fugl-meyer assessment, upper limb (fma-ue) baseline score of 20 to 50 (inclusive of 20 and 50). * ability to communicate, understand, and provide appropriate consent. subjects should be able to follow two-step commands. * right- or left-sided weakness of the upper extremity. exclusion criteria * participant has implanted metallic or electronic devices in the head or neck * hemorrhagic stroke or a heterogenous lesion etiology * participant has a cardiac pacemaker or implanted or wearable defibrillator * participant skin in the stimulation area has open wounds, skin eruptions, swollen, infected, or inflamed areas, or skin abnormalities that could be cancerous * advanced cardiac, pulmonary, liver, kidney dysfunction or blood system disease * participant has a fever or shows clinical signs concerning for an infectious disease * other neurologic or musculoskeletal diseases that could interfere with the assessments of this study * low heart rate (\<60 bpm) from a cardiac conduction block or related etiology * participant has a history of trigeminal neuralgia * participant has a history of bell's palsy * history of cranial nerve neuropathy (including facial nerve injury), carotid surgery, vagotomy, or other surgical intervention on the vagus nerve * history of recurrent syncopal events * known or newly-discovered aneurysm or arteriovenous malformation * patients who have any terminal illness such that the patient would not be expected to survive more than 90 days * botox injections 12 weeks prior to or during therapy